Functional Group

Organic Compounds are classified by virtue of their individual functional group as evident below.

Alkanes, Alkenes and Alkynes are Hydrocarbons ie they are compounds of only Carbon and Hydrogen. These Compounds differs by virtue of the number of Carbon-Carbon bonds in their chemical structures. Alkanes are single bond C-C Hydrocarbons that confer Substitution Reactions. A good example of an Alkane is Propane with a molecular formula CH₃CH₂CH₃.

Alkenes are Hydrocarbons with C=C double bond e.g Propene CH₃CH=CH₂. Alkynes on the other hand are triple Bond C≡C Compounds as exemplified by Propyne: CH₃C≡CH. The presence of more than one bond in Alkenes allows for additional reactions.

Alkanols are identified by the hydroxy functional group -OH in the general molecular formula R-OH. Ethanol is the most popular Alkanol (Alcohol) with the molecular formula C₂H₅OH. When the Hydrogen atom of the Alkanol functional group is substituted by an Alkyl group R an Ether with the general molecular formula R-O-R is formed. An example of Ether is Ethoxy Ethane C₂H₅-O-C₂H₅.

The oxidation of Alkanols could give rise to intermediate compounds of either Aldehydes or Ketones. Aldehydes (Alkanals) with molecular formula RCH=O are carbonyl compounds of partial oxidation of Primary Ethanol as evident in Ethanal CH₃CHO. The other type of carbonyl compounds are Ketones (Alkanone) with molecular formula: R₂C=O. Ketones or Alkanones are products of partial oxidation of secondary Alkanols. A typical example of Alkanone (Ketone) is Acetone (2-Propanone) CH₃COCH₃.

Halides are the halogen products of organic compounds. They are represented by the general formula of R-X. Where X = Halogen (e.g Fluorine, Chlorine, Bromine, Iodine). An example of Organic halide compound is the substitution product of Ethane CH₃CH₃: Bromoethane or Ethyl Bromide with the molecular formula C₂H₅Br.

Carboxylic Acid (Alkanoic Acid) are carboxyl group organic acids with molecular formula RCOOH. Ethanoic acid CH₃COOH is the most common Alkanoic Acid as evident in its use as Vinegar. Esters are the reaction products of Alkanols and Alkanoic Acids with the molecular formula RCOOR'. Where, R is an Alkyl group contributed by the carboxylic acid, and R' from Ethanol. An Example of an Ester is EthylEthanoate CH₃COOCH₂CH₃.

Thiol functional group R-SH is a substitution product of one hydrogen atom for a Sulphur-Hydrogen group to form an Alkylthiol compound. An example of thiol compound is Ethanethiol: C₂H₅SH.

Hydrocarbons also exist in another form that differs from the straight chain structure. This is the cyclic structure. Cyclohexane is an interesting example of cycloalkanes in that the structure is similar to Benzene except that while there is a delocalised double bond in the benzene structure, cyclohexane is a cyclical form of straight chain single bond Hexane. Cyclical structure of Hydrocarbons starts from the three carbon compound Propane (Cyclopropane) to the most complex.

Amines are represented by the general molecular formula: R-NH₂. They are a combination of Alkyl and Amino group. Ethanamine (also Ethylamine) C₂H₅NH₂ is a good example of Amine. Amides on the other hand, are more complex in that there is the addition of a carbonyl group C=O in the structure so that the formula becomes R-CONH₂. Acetamide (Ethanamide) CH₃CONH₂ is a typical example of an Amide.

The most important aspect of Nitro Compounds is the presence of a functional group conferred by Nitrogen and Oxygen in a Nitroxy functional group as evident in the general formula R-NO₂. An example of Nitro Compound is Nitromethane. Nitrites RC≡N on the other hand is made up of a Nitrogen functional group as evident in Ethanenitrile (Acetanitrile) CH₃≡N.